Insecticidal perchlorocarbon



2,934,470 INSECTICIDAL PERCHLOROCARBON John T. Rucker, Lewiston, N.Y., assignor to Hooker Chemical Corporation,Niagara Falls, N.Y., a corporation of New York g No Drawing. Original application .Iune 27, 1955, Serial No. 518,349. Divided and this application March 31, 1958, Serial No. 727,515

4 Claims. (Cl. 167-30) reductive coupling of hexachlorocyclopentadiene by hydrogen in the presence of a noble metal of group VIII having an atomic weight greater than 43 as a catalyst, with or without a solvent, at a temperature above about 20 degrees centigrade.

In preparing the compound of this invention, presumably in accordance with the following equation:

a solvent may or may not be employed; if a solvent is used, it should be inert with respect to the reactants and the reaction products. Among the solvents which may be employed are inexpensive and unreactive materials inert under the conditions employed, such as benzene, toluene, etc.

I have found that the choice of the catalyst is restricted to noble metals in group VIII of the periodic table which have an atomic number greater than 43. These metals are ruthenium, rhodium, palladium, osmium, radium and platinum whose atomic numbers are 44, 45, 45, 76, 77 and 78 respectively. Furthermore, I have found palladium 'to be the most satisfactory of these catalysts as well as being one of the least expensive of these particular elements. The catalyst to be used in the method of this invention is most effective when it is deposited on an inert carrier such as activated alumina, activated charcoal or kieselguhr preferably in a finely divided state. The amount of group VIII noble metal deposited on the carrier may be varied within wide ranges without materially effecting the reaction. I prefer to use as a carrier of powdered charcoal with palladium deposited therein in the amount of about 5 percent by weight. After treatment of the product the catalyst on the inert carrier or deposited catalyst is removed by hot filtration. Such deposited catalysts are available in commercial forms ranging from 1 to 20 percent of a noble metal deposited on the inert carrier. The concentration of the catalyst to be used during the reductive coupling may be varied in wide ranges without materially effecting the reaction; in general the catalytic .amount is all that is required. Catalyst concentrations containing about 0.001 to about 0.5 percent by weight of the metal based on the weight of the starting material have been found to be effective. When desirable, deposited catalyst concentrations as high as 10 percent may be used without detrimental effect except perhaps, on economy. I have also found the catalyst may be re-used many times with very little reduction in its activity. Further, I have found that when the catalyst finally does lose a substantial amount of its activity, it can be reactivated by washing and heating to a dull redness under an inert atmosphere.

It is preferred to perform the reaction at approximately room temperature. Lowering the temperature of the reaction increases operaitonal costs such as cooling; whereas this increased cost is not compensated by increased yields. Elevated reaction temperatures only serve to increase the yield of by-products.

The compound of this invention is useful as a chemical intermediate, for example, C Cl may be chlorinated to produce 0 C1 having a melting point of 221 to 223 degrees centigrade as more fully described hereinafter, which material is disclosed and claimed in copending application filed of even date herewith in the name of Earl T. McBee and James D. Idol, Ir. Further, C Cl may be thermally dechlorinated to produce C Cl Still further, C Cl is useful as an insecticide as exemplified hereinafter.

EXAMPLE 1 Preparation Twenty grams of hexachlorocyclopentadiene and one gram of catalyst consisting of 5 percent palladium-oncarbon powder, were charged into a two liter round bottom flask equipped with a thermometer, a reflux condenser, and a heating or cooling means. Gaseous hydrogen was bubbled into the mixture with stirring at a. temperature of 30 to 40 degrees centigrade. The effluent gases were scrubbed with water to remove any hydrogen chloride evolved. After six hours, one mole of hydrogen chloride was evolved for every four moles of hexachlorocyclopentadiene charged and the reaction was stopped. The catalyst was removed by filtration at a temperature of 28 degrees centigrade. The resultant black filtrate Was cooled to 12 degrees centigrade, then 5.8 grams ofv the white crystalline product (30% by weight) was separated by filtration. The product was recrystallized from isopropyl alcohol and then from hexane to give 5.6 grams of odorless crystals (28%). These crystals were analyzed and found to possess a melting point of about to 122 degrees centigrade, a chlorine content of 74.2 percent by weight, a molecular weight of 460; which corresponds to C Cl having a theoretical chlorine content of 74.60 percent by weight, and a theoretical molecular weight of 475, respectively.

EXAMPLE 2 The method of Example 1 was repeated except that 20 grams of hexachlorocyclopentadiene was dissolved in toluene in the presence of a palladium-on-carbon catalyst. The product was recovered as in Example 1 and con tained 5.9 grams of odorless crystals. These crystals were admixed with the product of Example 1 and showed no depression of melting point.

4 2,934,470 3 W re EXAMPLE 3 Use as chemical intermediate tallized from benzene giving 4 grams (75%) of C Cl as colorless needles, melting point of 221 to 223 degrees centigrade. C Cl is disclosed in copending application filed of even date herewith in the name of Earl T. McBee, and James D. Idol, Jr.

EXAMPLE 4 Use as chemical intermediate A solution of 50 grams of C Cl prepared as in Example 1 in 200 milliliters of carbon tetrachloride was placed in a Vycor tube 50 millimeters in diameter by 250 millimeters long, equipped with a gas dispersion disk,

- internal cooling coils and a reflux condenser. The tube was irradiated by two fluorescent lamps while chlorine was admitted into the solution for twelve hours while maintaining the temperature at approximately degrees centigrade, after which the solution was recovered from the tube and the solvent evaporated. The residue was dissolved in 150 milliliters of benzene, decolorized with Norite, then filtered. The clear filtrate was heated to remove benzene which resulted in the formation of colorless needle-like crystals. These colorless crystals were analyzed and found to possess a melting pointof about 221 to 223 degrees centigrade, a chlorine content of 78.05 and 77.89 percent by weight; a carbon content of 22.12 percent by weight, which corresponds to (3 01 having a theoretical chlorine content of 77.98 percent by weight and a theoretical carbon content of 22.01

I percent by weight.

crystals were analyzed and found to possess a melting point of 345 to 347 degrees centigrade, a chlorine content of 70.12 and 70.15 percent by weight which corresponds to C Cl having a theoretical chlorine content of 70.3 percent by weight. C Cl is disclosed in copending application filed of even date herewith in the name of Charles F. Baranauckas.

A 25 percent by weight dust of the perchlorocarbon, C Cl prepared as above, having a melting point of 345 to 347 degrees centigrade was made by intimately mixing the perchlorocarbon with a solid inert carrier, such as talc. This formulation which had the C Cl as the only insecticidal active ingredient product a100 percent knockdown in a period of twenty-four hours, when applied in a contact knock-down test to the confused flour beetle (Trbolium confusion). This indicates the usefulness of the compound as an ingredient in insecticidal compositions, contributing high knock-down quality thereto. The dust is equally effective against other species of insects and this example is not to be construed as limiting the insecticidal usefulness of the compound.

The compound of this invention is capable of being diluted with a solvent, such as benzene, to form solutions or dispersions which are effective against mites, such as Tetranychus atlanticus, and Tetranychus bimaculatus. This new insecticide may be applied in any of the conventional methods. Thus, for example, it may be used in an aqueous emulsion or it may also be incorporated in organic liquids such as the aromatic hydrocarbons for spraying purposes. It may be eifectively used in dusts with such inert solid diluents as kieselguhr, wood flour, walnut shell, talc and the like. More particularly, 0.2 gram of C Cl as in Example 1, may be mixed with a solvent, such as benzene, and an emulsifying agent to form an emulsifiable formulation which is then diluted to 200 milliliters with water. The following table shows the hills obtained under comparable conditions for the drochloric acid, then the organic layer was separated and washed with water and dried. Evaporation of the solvent left 3.7 grams of very light yellow crystals with a melting point of 485 degrees centigrade. An equal mixture of this product and that prepared as in Example 1, of a copending application filed of even date herewith in the name of Arnold N. Johnson did not result in a depressed melting point.

EXAMPLE 5 Use as chemical intermediate and found to possess a melting point of 344 to 346 degrees centigrade. The original precipitate was recrystallized twice from a :50 mixture by volume of benzene and glacial acetic acid. Thirteen grams of solid white crystalline material were recovered representing an overall yield of 85 percent by weight. These white various dilutions when the sprays were applied to specific mites.

TABLE Number Percent Insect Percent of Insects Kill Dilution Used (After 5 days) Tetrcmychus bimaculatua- 0. 1 50 D 0.05 49 96 0. 1 50 100 0.05 50 100 2. A process for protecting material susceptible to attack by insects which comprises applying to said mate- 5 rial an efiective amount of a perchlorocarbon having the 4. A process for destroying insects which comprises formula exposing the same to a lethal concentration of I n o a a v 01 01 01 and an inert insecticidal ad uVant as a earner therefor.

and an inert insecticidal adjuvant as a carrier therefor. 10 References Cited in the file of this Patent 3. A process for destroying insects which comprises UNITED STATES PATENTS exposing the same to a lethal concentration of 2,316,962 Lynn 20, 1943 2,732,409, Ladd Jan. 24, 1956 15 2,837,579 Buntin June 3, 1958 OTHER REFERENCES Hackh: Chem. Dictionary, 3rd ed., 1944, McGraw-Hill, p. 270.

UNITED STATES PATENT OFFICE CERTIFICATE r coRRscTIoN Patent No. 2334 470 v April 269 1960 John T Rucker It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below. I

Column 2 line 14 for "operaitonal" read operational line 24 after "Jre." insert g which issued August 26 1959 as US patent number 2 849,499. column 3, line 13 after "in" insert the aforesaid line 52 after "appli== cation" insert SN 5l8 34O column 4 line 7 after "Charles F. Baranauckas" and before the period insert V which issued on July 30 1957 as US patent number 2 801369 line 13 for "product" read produced line 59 after "inventions" insert the following paragraph:

This application is a continuing appli== cation based upon my copending application Serial No, 518 349, filed June 27 1955 which issued as US Patent No, 2,908,723 on Oct, 13, 1959.3

Signed and sealed this 18th day of April 1961.

(SEAL) Attest: v

ERNEST Wo SWIDER DAVID L. LADD Attest'ing Officer Commissioner of Patents 

1. A PROCESS FOR PROTECTING MATERIAL SUSCEPTIBLE TO ATTACK BY INSECTS WHICH COMPRISES APPLYING TO SAID MATERIAL AN EFFECTIVE AMOUNT OF A PERCHLOROCARBON HAVING THE FORMULA 